Gen. David Petraeus, shown testifying to Congress in June 2010, resigned as CIA director in the wake of an extramarital affair scandal. / Pablo Martinez Monsivais, AP

by John Bacon, USA TODAY

by John Bacon, USA TODAY

Former CIA director David Petraeus agreed Wednesday to testify before Congress concerning the Sept. 11 attack on the U.S. Consulate in Libya, while a group of Republican senators called for a Watergate-style congressional committee to investigate the attack.

She provided no timetable. Fox News reported that the former general is expected to speak Friday to the Senate Intelligence Committee about the attack on the compound in Benghazi, and that details for testimony on the U.S. House side were still being worked out.

Petraeus was initially slated to offer testimony on the attack, which left U.S. Ambassador Christopher Stevens and three others dead, at a closed hearing before the Senate committee Thursday.

Petraeus, a former general, resigned last week over an extramarital affair with writer and former Army officer Paula Broadwell. The resulting investigation has since expanded to include Gen. John Allen, the top U.S. commander in Afghanistan. Allen reportedly exchanged "possibly inappropriate" e-mails with Jill Kelley, a Florida socialite linked to the Petraeus scandal.

Asked if there was a national security breach with the Petraeus affair, Feinstein said, "I have no evidence that there was at this time."

Meanwhile, Arizona Sen. John McCain and other Republican senators called for establishment of a special congressional panel to investigate the attack.

"His last message was that he was concerned about security" at the compound in Benghazi, McCain said of Stevens. "Four Americans died.

"The State Department probes the State Department. We want to probe everybody involved, all the way up to and including the president of the United States."

McCain said the investigation is necessary to discover the truth behind what happened, including Broadwell's assertion in a Colorado speech that the attack in Benghazi was launched to free detainees being held at the CIA annex there. The CIA denies there were any Libyans being held at the compound.

"This person (Broadwell) who was associated with Gen. Petraeus said at some gathering (in Colorado) there were two or three Libyans in the CIA safe house. The CIA said that was patently false," McCain said. "We don't know and that's why we need an investigation."

The attack became a heated campaign issue leading up to the presidential election. Reports surfaced that U.S. diplomats had questioned the level of security at the consulate. And Republicans criticized the Obama administration's failure to more quickly acknowledge that intelligence suggested very early on that it was a planned terrorist attack.

McCain, the top Republican on the Senate Armed Services Committee, said he would do all he could to block Susan Rice from becoming the next secretary of State if President Obama nominates her, noting that five days after the attack, Rice said the attack was the result of an angry response to an anti-Muslim video.

The administration also has taken criticism for what was perceived as a slow response to the attack. Defense Secretary Leon Panetta has said the U.S. military did not quickly intervene during the attack because military leaders did not have adequate intelligence information and felt they should not put American forces at risk.